System and method for locating objects

ABSTRACT

A plurality of location beacons is deployed within a site that is divided into zones. A plurality of assets is distributed within the site, each asset having an asset beacon attached to it. A tag occasionally moving within the site continually locates its current zone by detecting short-range signals received from location beacons, and when detecting an asset beacon, the tag locates the respective asset within the current zone of the tag.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefits of U.S. provisional patentapplication No. 62/214,936 filed on 5 Sep. 2015; this application isrelated to a patent application by the present inventor titled SYSTEMAND METHOD FOR MULTI-LEVEL BORDER CONTROL WITHIN SITES, filedconcurrently with the present application; the contents of both relatedapplications are incorporated by reference in their entirety as if setforth herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to locating objects, and in particular tolocating assets and people within institutional sites.

Description of Related Art

RTLS (real time location services) systems are commonly used to locateobjects, such as assets or people, within institutional sites such asmanufacturing plants, warehouses, healthcare facilities or retailstores.

A typical RTLS system includes an infrastructure of fixed activedevices, each located at a known location, and movable active devices,each associated with a known object. The fixed and movable activedevices are adapted to establish short-range communication via anultrasonic, infrared or low-power RF signal, and at least one of thefixed or movable active devices connects via a network to reportmeetings between respective active devices. Each meeting reportindicates that the current location of the object associated with themovable active device is in proximity to the known location of the fixedactive device, thereby providing real time location information relatedto the respective object.

The resolution of the detected location can be improved in a variety ofways, such as: a shorter communication range and higher number of fixedactive devices; analyzing the signal strength, sometimes is associationwith the battery level, for estimating the current distance between thereported devices; or using triangulation for analyzing a plurality ofsimultaneous short-range signals associated with a single movable activedevice and a plurality of fixed active devices.

A typical RTLS system requires substantial investment in sensing andcommunication infrastructures throughout the site. While some sitesjustify such investment by effectively and quickly locating criticalequipment or personnel, and others show high returns from targetedadvertising, there are still many other sites, that could benefit fromquickly locating objects, and cannot afford or justify the expenseassociated with deploying the respective sensing and communicationinfrastructure of a common RTLS system.

The present disclosure comes to teach locating systems with highlyreduced sensing and communication infrastructures, and some applicationsof such systems.

BRIEF SUMMARY OF THE INVENTION Definitions

An “institutional site”, abbreviated “site”, is a managed place that isrun by a “staff”. Examples of sites include manufacturing plants,warehouses, healthcare facilities or retail stores. A “staff member” isan employee or volunteer operating in a site. A “mover” is a staffmember designated to move an asset to a specified target location. Beinga mover may be the main job of a staff member, or an occasionalincident. A site may accommodate additional persons that are not staffmembers, such as residents, customers or visitors.

An “asset” is a thing that may be needed for a useful purpose. Peopleare not considered herein assets, and the term “object” will be usedherein to refer to both people and assets that need to be located. An“asset identifier”, such as an inventory number, uniquely identifies anasset within a site. An asset identifier may also include ahuman-comprehensible “asset description” to describe an asset to staffmembers; examples for asset descriptions are the respiratory machine,respiratory machine no. 37, or the yellow respiratory machine.

An “active device” is an electronic devices capable of transmittingand/or receiving data.

A “smart tag”, abbreviated “tag”, is herein an active device that playsa role in locating objects and is capable of communicating locationinformation. Smart tags include “personal tags” borne by persons,“assets tags” attached to assets, and “fixed tags” that are fixed at alocation. In a healthcare facility, personal tags include “staff tags”and “resident tags” borne by staff members and residents, respectively,or may further include “visitor tags” borne by visitors. A tag ispreferably configured according to the respective role and identity ofthe person, asset or location associated with the tag. A personal tagmay be a dedicated device assigned to a person, or a privatecommunication device of a person, such as a smartphone, programmed tofunction as a tag.

A “beacon” is an active device recurrently transmitting a short-rangesignal for being received and read by tags that are within a shortmaximum range, the preferred maximum range being between a meter and afew tens of meters, depending on the application. A “location beacon” isfixed to a specific location within a site, such as on a wall or aceiling; an “asset beacon” is attached to an asset and moves with theasset; while a “personal beacon” is borne by and moves with a person.The term “attached to an asset” covers also the case where the beaconforms an integral part of the asset. As long as a certain object beaconis known to be borne by or attached to a certain object, expressionssuch as “detecting an object”, “detecting an object beacon”; “locatingan object”, “locating an object beacon”; “receiving a signal from anobject”, or “receiving a signal from an object beacon”; may be usedinterchangeably. The short-range signal transmitted by the beaconpreferably uses low-power RF, ultrasound or infrared to carry the“beacon identifier” uniquely identifying the beacon within the site, andpossibly also information regarding the battery level of the beacon,and/or object status information received by the beacon from an objectby which the beacon is borne or to which the beacon is attached. Abeacon short-range signal is read by a compatible receiver that formspart of a tag or another signal detecting device, to identify the beaconand possibly also identify the object by whom the beacon is borne towhich the beacon is attached, as well as to optionally receive otherinformation carried by the signal. A receiver may also measure thestrength of the short-range signal received from a beacon, which may beindicative of the current distance between the receiver and the beacon,which is similar to the distance between the tag and the object.iBeacon, marketed by numerous vendors in compliance with a standardpublished by Apple, Cupertino, Calif., is an example of a beacon thatuses BLE (Bluetooth low energy) for its short-range signal, while avariety of contemporary smartphones can be programmed to act ascompatible receivers.

A “visual feature” is a distinguishable visual mark, symbol, pattern,image or color that can be captured by a camera and processed by animage processor to identify a location, an object or an object type.Visual features may be invisible to the naked eye, for example by usingink in the infrared wavelength, as long as the respective cameras cansee them and use appropriate filters, if needed. In the present context,visual features may be borne by objects or fixed to locations, andfunction similarly to beacons, if respective tags are adapted to detectand recognize them.

“Bearing” a tag, a beacon or a visual feature by an object willgenerally relate to a person carrying or wearing a tag, a beacon or avisual feature, or an asset having a tag, a beacon or a visual featureattached thereto or embedded therein.

It shall be appreciated that some active devices may function as bothtags and beacons. Thus, a tag may locate another tag via short-rangecommunication.

Databases that are stored in or are accessible by tags may correlateobject identifiers with beacon identifiers and object descriptions, andit is presumed herein that providing an object identifier to a tag makesthe corresponding beacon identifiers and/or asset descriptions readilyavailable to the tag.

“Locating” an object means obtaining information pertaining to thecurrent location of the object, while “directing” toward an object meansproviding human-comprehensible directions to a person for reaching theobject according to its location.

SUMMARY

The following discussion mostly uses examples pertaining to healthcarefacilities. However, it shall be appreciated that the teachings of thepresent disclosure relate to a variety of other institutional sites aswell.

The present disclosure recognizes that, under certain circumstances, alocating and directing system can be highly simplified by realizing, andmaking use of the fact, that assets are usually moved by staff members;that staff members are often intelligent, experienced persons who arefamiliar with the assets and the site and typical locations where assetsare used or parked, and have eyes; and that staff members oftenaccidently pass by assets in the course of performing their routineduties.

The following concepts will facilitate the understanding of the presentdisclosure:

“Zoning” is a division of a site into relatively large zones, servingfor roughly locating objects. The term zoning will also be used hereinto denote the act of zone-level locating of an object, i.e. identifyingthe zone in which an object resides. It is assumed that, under certaincircumstances, zoning may be good enough for effective, timely locatingof objects; for example, a staff member requested to “fetch arespiratory machine from the West Zone on the 3^(rd) floor” will oftenreach the machine pretty quickly, maybe just a few seconds later thanwhen being requested, in another similar site employing a common,fully-fledged RTLS system, to “fetch a respiratory machine from next tobed C in room 305”. Zones may partly overlap, thus zoning may affordsome level of ambiguity, as will be elaborated later below.

“Homing” is a method for directing a user holding a receiver toward atarget asset having an asset beacon, by seeking a short-range signaltransmitted by the target asset, and when the short-range signal isdetected, continuously monitoring the short-range signal for approachingthe asset, for example by exhibiting a series of human-comprehensiblehoming directions toward the asset, based on the receiver providing tothe user a series of visual and/or audio indications of the currentmeasured strength of the signal received from the beacon, that may bepresented in terms of estimated distance, which intuitively leads theuser to seek stronger signals hence approach the asset. In moresophisticated systems, homing may provide explicit directionindications, such as by displaying an arrow pointing at the asset.Homing may complement zoning for fast screening of larger zones,including, for example: for finding the asset faster; for distinguishinga sought specific asset from other similar assets; for finding assetsthat hide behind curtains that are permeable to the beacon's short-rangesignal; for indicating, by an absence of a beacon signal, that thesought asset is not within a certain part of the zone; or just forverifying that the related asset is in the zone without physicallyapproaching the asset.

“Greeting” is an asset location report message authored and sent by atag that has detected the beacon of the asset, thereby associating thelocation of the asset with the zone of the tag. A greeting may beinformally described as a messages sent by a tag to a recipient,stating: I am currently in zone X and have just seen asset Y. In atypical healthcare facility, for example, many tags are continuallypassing by assets, purposely or accidently, providing a continuousseries of greetings that serve to dynamically locate assets, as will befurther elaborated below.

“Escorting” is an event of detecting continuous close proximity betweena tag and an asset beacon maintained for a prolonged duration, saythirty seconds or more, while also detecting that the tag has moved asubstantial distance, say several meters or more, during the duration ofthe close proximity. An escorting event may be interpreted as adisplacement of the respective asset by the person bearing the tag. If astaff member has been commissioned to move a certain asset to bed C inroom 305, then the respective escorting event may indicate by defaultthat at the end of the escorting event the asset is located next to bedC in room 305.

According to preferred embodiments of the present invention there isprovided a method of operation of a tag for locating assets, the tag isfor being borne by and occasionally moving with a user within a sitethat is divided into a plurality of zones, the method including:receiving a second short-range signal from an asset beacon attached toan asset; retrieving from the second short-range signal anidentification of at least one of the asset beacon or the asset;wirelessly reporting the current zone to a recipient; and wirelesslyreporting the identification to the recipient.

The method may further include: checking the availability of a networkconnection, and either or both of the reporting the current zone or thereporting the identification is postponed until the network connectionis available. The current zone and the identification of the asset orasset beacon may be included within a single locating message, or bereported separately, when available. It will be noted that reporting thecurrent zone and reporting the identification of the asset beacon or theasset are preferably made automatically according to predefined rules,without requiring human initiative or action.

The method may serve a user who is a staff member bearing a staff tagthat is further operative for directing the staff member toward targetassets, by receiving a target asset identifier and a target zoneassociated with a target asset; presenting to the staff member adescription of the target asset; and presenting to the staff memberdirections for reaching the target zone.

If the staff member is designated to relocate the target asset, themethod may further include: receiving a relocation assignmentidentifying a target location for the target asset; detectingshort-range beacon signals transmitted by a beacon of the target asset;learning from the beacon signals that the staff tag and the beacon arein close proximity; measuring the duration of the close proximity;checking whether the staff tag has moved while the close proximity ismaintained; and, based on the results of the measuring and the checking:locating the target asset at the target location.

The method may also include: seeking beacon signals that match a beaconidentifier of a beacon attached to the target asset; and, upon detectinga beacon signal that matches the beacon identifier: producing a seriesof human-comprehensible homing directions for approaching the targetasset.

The directions for reaching the target zone may include a name of thetarget zone or instructions for reaching the target zone. The step ofpresenting directions may include displaying text instructions,displaying graphical guidance, or playing audio instructions. The stepof producing a series of homing directions may include displaying atextual representation of a current strength of the detected beaconsignal, displaying a textual guidance regarding the direction of thebeacon, displaying a graphical representation of a current strength ofthe detected beacon signal, displaying a graphical guidance regardingthe direction of the beacon, playing an audio signal that is indicativeof the current strength of the detected beacon signal, or playing anaudio guidance regarding the direction of the beacon.

Also provided is a method of operation of a tag of a person fordirecting the person toward target assets, the method including:receiving a target asset identifier and a zone associated with thetarget asset; presenting to the person a description of the targetasset; presenting to the person directions for reaching the zone;seeking beacon signals that match a beacon identifier of a beaconattached to the target asset; and upon detecting a beacon signal thatmatches the beacon identifier: producing a series ofhuman-comprehensible homing directions for approaching the asset. If theperson is a staff member designated to relocate the target asset, themethod may further include: receiving a relocation assignmentidentifying a target location for the target asset; detectingshort-range beacon signals transmitted by a beacon of the target asset;learning from the beacon signals that the staff tag and the beacon havereached close proximity; measuring the duration of the close proximity;checking whether the staff tag has moved while the close proximity hasbeen maintained; and based on the results of the measuring and thechecking: locating the target asset at the target location.

Also provided is a tag for locating assets, the tag is for being borneby and occasionally moving with a user within a site that is dividedinto a plurality of zones, the tag including: a short-range signalreceiver; a network communication device; and a processor controllingthe short-range signal receiver and the network communication device,the processor is programmed to: receive a first short-range signal froma location beacon associated with a current zone of the plurality ofzones, receive a second short-range signal from an asset beacon attachedto an asset, retrieve from the second short-range signal anidentification of at least one of the asset beacon or the asset,wirelessly report the current zone to a recipient, and wirelessly reportthe identification to the recipient.

The processor of the tag may be further programmed to check theavailability of a network connection, and at least one of the report thecurrent zone or the report the identification is postponed until thecheck is positive. The processor may include both reporting the currentzone and reporting the identification within a single locating message,or report them separately, when available.

If the user is a staff member bearing a staff tag that has a userinterface for directing the staff member toward target assets, theprocessor of the tag may be further programmed to: receive a targetasset identifier and a target zone associated with a target asset,present to the staff member a description of the target asset, andpresent to the staff member directions for reaching the target zone.

If the user is a staff member bearing a staff tag, and the staff memberis designated to relocate the target asset, the processor is furtherprogrammed to cooperate with the short-range signal receiver and thenetwork communication device to: receive a relocation assignmentidentifying a target location for the target asset; detect short-rangebeacon signals transmitted by a beacon of the target asset; learn fromthe beacon signals that the staff tag and the beacon have reached closeproximity; measure the duration of the close proximity; check whetherthe staff tag has moved while the close proximity has been maintained;and, based on the results of the measure and the check: locate thetarget asset at the target location.

The processor of the tag may be programmed to cooperate with theshort-range signal receiver to: seek beacon signals that match a beaconidentifier of a beacon attached to a target asset; and upon detecting abeacon signal that matches the beacon identifier: produce a series ofhuman-comprehensible homing directions for approaching the target asset.

Also provided is a tag of a person for directing the person towardtarget assets, the tag including: a short-range signal receiver; anetwork communication device; a user interface; and a processorcontrolling the short-range signal receiver, the network communicationdevice and the user interface. The processor is programmed to: receivevia the network communication device a target asset identifier and azone associated with the target asset; present to the person via theuser interface a description of the target asset; present to the personvia the user interface directions for reaching the zone; seek via theshort-range signal receiver beacon signals that match a beaconidentifier of a beacon attached to the target asset; and upon detectinga beacon signal that matches the beacon identifier: produce via the userinterface a series of human-comprehensible homing directions forapproaching the asset. If the person is a staff member designated torelocate the target asset, the processor may be further programmed to:receive via the network communication device a relocation assignmentidentifying a target location for the target asset; detect via theshort-range signal receiver short-range beacon signals transmitted by abeacon of the target asset; learn from the beacon signals that the stafftag and the beacon have reached close proximity; measure the duration ofthe close proximity; check whether the staff tag has moved while theclose proximity has been maintained; and, based on the results of themeasuring and the checking: locate the target asset at the targetlocation.

It will be noted that when locating objects is described as based onanalyzing short-range communication between a fixed active device and amoving active device, additional fixed active devices may concurrentlycommunicate with the same moving active device, for increasing locationmeasurement resolution and accuracy, for example by triangulation. Suchlocating techniques are well-known in the art, and may be selectivelyimplemented in the appropriate cases, even if they are not explicitlydescribed.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description, taken in conjunction with thedrawings in which:

FIGS. 1A-1B are block diagrams describing systems according to preferredembodiments of the present invention.

FIGS. 2A-2F are schematic illustrations of floor layouts of preferredembodiments of the present invention.

FIG. 3 is a schematic illustration depicting asymmetry purposelyincluded in a zone border beacon according to a preferred embodiment ofthe present invention.

FIGS. 4A-4C are flowcharts describing asset locating processes accordingto preferred embodiments of the present invention.

FIG. 4D is a schematic illustration of the contents of a greetingaccording to a preferred embodiment of the present invention.

FIG. 4E is a block diagram depicting distribution of greetings accordingto preferred embodiments of the present invention.

FIG. 5 is a flowchart depicting the detection of escorting eventsaccording to a preferred embodiment of the present invention.

FIG. 6 is a flowchart depicting a process of directing a staff membertoward an asset according to a preferred embodiment of the presentinvention.

FIGS. 7A-7C are schematic illustrations that pertain to homing,according to preferred embodiments of the present invention.

FIGS. 8A-8B are schematic illustrations that describe floor layouts thatinclude blind areas.

FIG. 9A is a block diagram of an enhanced smart device according to apreferred embodiment of the present invention.

FIG. 9B is a schematic illustration that depicts a floor layout fordemonstrating exemplary smart device implementations.

FIGS. 10A-10C are schematic illustration of floor layouts that pertainto multi-level border security.

FIGS. 11A, 11B and 12 are flowcharts describing the process of operatinga multi-level border control system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The System

FIG. 1A is a block diagram depicting system 100A according to apreferred embodiment. Each tag 110 of plurality of tags listens toshort-range signals that may be transmitted by each asset beacon 150 ofa plurality of asset beacons. Tag 110 also listens to short-rangesignals that may be transmitted by each asset location beacon 160 of aplurality of asset location beacons. Tag 110 sends location reports toone or more recipients having a location data store 170, and, if tag 110is of a staff member that may be assigned to approach assets, tag 110may also communicate with one or more control 174 for receivingasset-related assignments therefrom.

Tag 110 includes short-range signal receiver 114 that listens to signalssent by beacons and detects, from signals received from a beacon, thebeacon identifier, and may also measure the strength of receivedsignals. Optionally, short-range signal receiver 114 also retrieves froma signal received from a beacon other information, such as a messagefrom an asset relayed via the respective asset beacon. One or more ofnetwork communication device(s) 118, is used for establishingcommunication via a communication network, such as a Wi-Fi, cellular orBluetooth network, with location data store 170, and optionally alsowith control 174. User interface 122 provides information to the tag'suser via visual and/or audio and/or tactile signals. Memory 126 storesdata, while processor 130 includes processing hardware and software forthe operation of tag 110, including the methods taught by the presentdisclosure. Battery 134 energizes all the units of tag 110. Sensors 138,such as an accelerometer, compass, microphone or camera, may be used todetect whether tag 110 is in use or is in motion, and also optionallyparticipate in determining the location of tag 110. Optional otherfunctions 146 are hardware and software components that serve for thetag offering useful functionalities that are unrelated to the presentinvention, such as music playing, telephony or outdoors navigation.Optional attachment 142, such as a lanyard, a belt or a clip, may beused to conveniently attach tag 110A the tag bearer's body or clothing.Tag 110A may also be carried in the bearer's handbag or pocket, forexample in the case that the tag is actually implemented as a personalsmartphone programmed according to the teachings of the presentdisclosure.

Asset beacon 150 is a transmitter of a short-range signal, such as anultrasonic, infrared or low-power RF signal, that is assigned andattached to an asset and effectively becomes part of the asset. It isenergized from either a battery (not shown) of from power provided bythe asset. Asset beacon 150 is devised to recurrently transmit ashort-range signal, for allowing receivers, such as short-range signalreceiver 114 of tag 110, to detect the presence and retrieve theidentity of the respective asset. Short-range signal transmitter 152transmits the above short-range signal carrying asset beacon identifier154 and/or asset identifier 156 and optionally messages received fromthe respective asset via asset interface 158. Asset beacon identifier154 is recorded within asset beacon 150 to uniquely identify assetbeacon 150 within the site. Asset identifier 156, such as an inventorynumber and/or an asset description, is optionally recorded within assetbeacon 150, or it can be retrieved from a lookup table (not shown)includes in the tag's memory 126 or in location data store 170, againstasset beacon identifier 154. Asset interface 158 is optionally included,typically for more sophisticated and expensive assets, for relaying, viashort-range signal transmitter 152, asset-related status messages suchas usage, need for maintenance etc., and can also be used for supplyingpower from the asset for the operation of asset beacon 150.

Location beacon 160 is fixed at a known, selected spot, such as on awall or a ceiling within the site, for identifying the current zone of atag 110 that currently communicates with location beacon 160 viashort-range communication. Location beacon 160 uses short-range signaltransmitter 162 to transmit its location beacon identifier 164, which,when received by short-range signal receiver 114 of a tag 110,identifies the current zone in which tag 110 is currently located. Thetransformation from location beacon identifier 164 to the current zoneis made by either processor 130 of tag 110 or at the location data store170, using a site map that correlates each location beacon identifier164 with its actual location within the site. Location beacon 160 can beclassified into zone-border beacon or zone-center beacon, as will beelaborated later below.

Location data store 170 receives location data reports, also calledherein greetings, from tags 110, and stores the received data for beingused by control 174. The location data is preferably organized as adatabase or another data structure, and correlates asset beaconidentifiers and/or asset identifiers with the current known location ofeach asset. Location data store 170 may be stored on a site server orinternet server, on a desktop, laptop or tablet computer or asmartphone, or within memory 126 of tag 110 assigned to a staff memberwho is in charge of asset management or operates control 174. Severalunits of location data store 170 may operate concurrently, for exampleto serve different types of assets controlled by different controls 174,or just carry redundant copies of the same asset location data.

Control 174 is a computerized command post, that includes a processor,and is in a form such as a computer, a tablet, a smartphone or a stafftag, allowing a supervisory staff member, such as an asset manager,shift supervisor or chief nurse, to assign asset-related assignments toother staff members via their tag 110. When an asset-related assignment,such as maintaining or moving the asset, or authorization to move anasset, is assigned to a staff member bearing a tag 110, the tag willdirect the staff member toward the asset, as will be described laterbelow.

FIG. 1B describes system 100B, that is an alternative embodiment thatdoes not use the location beacons 160 of FIG. 1A. Instead, one or moreof location sensor 138L serve to identify the current zone where tag110A is. Examples of location sensor 138L will be described in thesection LOCATING TAGS WITHOUT USING LOCATION BEACONS below. It will beappreciated that hybrid configurations, that mix both location beacons160 of FIG. 1A and one or more methods that do not use location beaconsare also feasible, and may be the preferred choice for some sites.

Zoning

Zoning a site into relatively large zones serves for roughly defining alocation of an object. Such division is site-specific, and may be mademanually by an administrator under the following considerations: (a)easy recognition of the zone by staff members, for example: “the WestZone on the 3^(rd) floor” or “the imaging division”; (b) efficient andconvenient deployment of location beacons or visual features used foridentifying the zones (FIGS. 2B and 2C below), if such elements areapplied; (c) the zone size and layout are easy to manually screen by amoving staff member for finding an asset within the zone; and (d)preferably, effective separation among zones, for example by walls thatare impermeable to beacon signals, so that leaks of asset beacon signalsbetween zones are eliminated or reduced.

FIG. 2A schematically describes an exemplary division of a floor layoutin a healthcare facility into four zones: Elevator Zone near theelevator; West Zone that includes six 3-bed rooms; East Zone thatincludes three single-bed rooms, and South Zone that is a corridorconnecting the east and West Zones. It will be noted that zone names maybe arbitrarily chosen by an administrator to be uniquely and easilyrecognized by the staff, and can be names of divisions, functional namessuch as the dining area, or legacy names such as “Roberta's hall”.

Locating an Asset

Locating an asset is at least determining the zone in which the asset iscurrently located. In some cases, when additional information isavailable, as is the case of detecting an escorting event by adesignated mover, such additional information may provide more specificlocation information; for example, instead of just locating arespiratory machine at the West Zone, it may be located next to bed C inroom 305, according to the particulars of the moving assignment sent tothe designated mover.

Locating an asset is usually a two-stage process: (i) locating a tag;and (ii) detecting the asset's beacon by the tag via a short-rangesignal. This locating process works best when the maximum range of theshort-range signal is small relatively to the zone's size, and/or whenzones are physically separated by walls that are impermeable to orhighly attenuate the short-range signals. As noted above, the locatingprocess may be supplemented by additional location information, as inthe case of an escorting event by a designated mover.

It will be noted that locating the tag and detecting the asset's beaconmay be separate events. For example, a staff member's tag detects itsentry into the West Zone at 10:00 am, while the tag detects an assetbeacon at 10:03 am. Such events are usually combined and interpreted asthe respective asset being located at the West Zone at 10:03, especiallywhen the tag is expected to reliably detect its exit from the West Zone.

Using Zone Border Beacons for Locating Tags

A “zone border beacon” is herein a location beacon positioned on or nextto a border between zones, for allowing tags to detect their enteringand/or exiting the respective zones. In some of the following exemplaryembodiments such location beacons will be described as fixed to theceiling; it will be appreciated, however, that location beacons mayalternatively be fixed to walls or to any stationary objects.

FIG. 2B schematically describes deployment of five zone border beacons220A-220E, devised for allowing tags to detect entry into and exit fromthe four zones of FIG. 2A. The zone border beacon is preferably fixed tothe ceiling or to a lintel, or possibly to a wall, on or next to theborder between the zones. Thus, zone border beacon 220E is positionedfor allowing tags to detect entry to and exit from the elevator into andfrom Elevator Zone; zone border beacon 220A and zone border beacon 220Bare positioned for tags detecting moving between the Elevator Zone andthe West Zone/East Zone, respectively; while zone border beacon 220C andzone border beacon 220D are positioned for tags detecting moving betweenthe South Zone and the West Zone/East Zone, respectively.

Detection by a tag of crossing the border between zones benefits fromthe short distance and clear line-of-sight between the tag and the zoneborder beacon, and by recognizing a peak in the strength or the signalreceived by the tag from the beacon. Deciding whether a border-crossingtag is entering or exiting a zone can be made by counting the number ofcrossings of the border by the tag. However, to avoid confusion, such aswhen a tag bearer turns around at the border between zones, asymmetry inthe zone border beacon design or in its installation is preferablyintroduced. FIG. 3 schematically describes a simplified asymmetricdesign, where zone border beacon 220A is fixed to ceiling 322, andshield 324, such as a small piece of material that is impermeable to theshort-range signal emitted from zone border beacon 220A, is also fixedto ceiling 322 to partially block the short-range signals emitted fromzone border beacon 220A in the direction of the West Zone. The beaconsignal strength detected by the tag is schematically depicted by curves330A+330B as a function of distance from zone border 326 (straightcurves are arbitrarily used for simplicity). Assuming that the tag moveswith its bearer at a fairly constant speed, the signal vs. time curvelooks similar to the signal vs. distance curve of FIG. 3. Thus, when thetag first detects moderate inclining slope signal strength curve 330Afollowed by sharp declining slope signal strength curve 330B, entry intothe West Zone is detected, while when the tag first detects incliningsharp slope signal strength curve 330B followed by declining moderateslope signal strength curve 330A, entry into the Elevator Zone isdetected. It will be noted that other designs that indicate thedirection of motion between zones may be applied, for example placing apair of beacons at the border between zones, and detecting which of thetwo respective peaks shows first.

Exemplary Floor Layout

FIG. 2B depicts an exemplary floor layout 200B in a healthcare facility,divided into the four zones of FIG. 2A. Elevator 204 is used to enterand exit the floor. The West Zone includes six rooms 210-1 to 210-6,each room hosting three beds A-C. The East Zone includes tree single-bedrooms 210-7 to 210-9. Zone border beacons 220A-220E serve tags visitingthe floor (not shown) for locating their current zones by detectingborder crosses, as discussed above. Assets 230A-230D are examples ofassets scattered throughout the floor, to be located according to theteachings of the present disclosure. Access points 206A-206C, such asWi-Fi access points, demonstrate partial network coverage of the floor,which allows a tag 110 to use its network communication device 118 (seeFIGS. 1A-1B) to report asset locating events only passing by an accesspoint.

Locating Tags without Using Location Beacons

FIG. 2C describes floor layout 200C that is similar to floor layout 200Bof FIG. 2B, with the omission of zone border beacons 220A-220E and withthe addition of visual features 244A-244D. Retaining the method oflocating an asset via combining locating a tag and detecting the asset'sbeacon by the tag, FIG. 2C focuses on using one or more of locationsensor 138L (FIG. 1B) as alternatives to detecting the zone borderbeacons of FIG. 2B. Turning opportunities 240A-240L are virtual spotswhere tags may make sharp turns into or from corridors and rooms. Suchturns are detectable by an accelerometer included in sensors 138, andmay sometimes be distinguishable from one another with the assistance ofa compass included in sensors 138.

With reference also to the zones defined in FIG. 1A, a tag detecting asharp right turn at the elevator exit (apparently at turning opportunity240A) followed by detecting a sharp left turn (apparently at turningopportunity 240B) may realize that the tag has entered the West Zone.However, when a further sharp right turn event is detected, it may behard to determine whether such event occurred in any of turningopportunities 240D-240F—which implies that the tag is located in one ofthe rooms of the West Zone, or at turning opportunity 240G—implying thatthe tag has crossed the border to the South Zone. To resolve suchambiguities, visual features 244A-244D are added, to be detected andrecognized by a camera that is included in sensors 138 and ispositioned, along with the tag, to look at the same direction as theuser bearing the tag. Thus, following the detection of the sharp rightturn described above, seeing or missing visual feature 244C by thecamera may indicate being at the South or West Zone, respectively.Visual features 244A-244D are distinctive marks, symbols, patterns,images or colors that are recognized by image processing of the imageviewed by the camera, and can be, for example, either arbitrary existingelements, such as a painting hung on the wall, or a sticker or signshowing conventional text of coded with a bar code or QR code. Acombination of analyzing all turning opportunities within a floorsupplemented by unique visual features positioned at key points mayprovide reliable locating for tags within the floor area, as analternative to location beacons.

Additionally or alternatively, other indoors positioning technologiesmay also be used for locating a tag. For example, U.S. Pat. No.8,798,924 teaches a method of using an electronic compass sensor todetect consistent irregularities in the earth's magnetic field caused bysteel structures embedded within buildings. The method has beenimplemented and marketed by IndoorAtlas Inc. of Palo Alto, Calif. Thus,including an electronic compass in sensors 138 of tag 110 andprogramming the method of the '924 patent above into processor 130provides another way for locating the current zone of tag 110 withoutdeploying location beacons.

Locating Tags Using Zone Center Beacons

A “zone center beacon” is a location beacon positioned within a zone,with the purpose of tags locating themselves within the zone upondetecting a short-range signal received from the zone center beacon, orupon detecting that the strength of the signal exceeds a predeterminedthreshold. It will be appreciated that the term “center” is merelyillustrative, and a zone center beacon may be located anywhere within azone, as long as detecting the beacon indicates being located within therespective zone. Also, a zone may have multiple zone center beacons (notshown in the following figures) that serve to identify the zone. In someof the following exemplary embodiments such location beacons will bedescribed as fixed to the ceiling; it will be appreciated, however, thatlocation beacons may alternatively be fixed to walls or to anystationary objects.

FIG. 2D schematically describes floor layout 200D, wherein fourteen zonecenter beacons 220-1 to 220-14 are fixed to the ceiling to definefourteen room-size zones. For example, when a tag detects zone centerbeacon 220-3 (or that the strength of the short-range signal receivedfrom zone center beacon 220-3 exceeds a predefined threshold), the tagis considered located within the respective room 210-1.

When comparing the exemplary layouts of FIGS. 2B and 2C, floor layout200D appear to offer an advantage of finer, room-level locatingresolution against the disadvantage of higher cost of deploying andmaintaining more location beacons. However, smaller zones imply alsoother disadvantages of false locating and reduced frequency ofgreetings, as will be elaborated in the section CORRELATION BETWEEN ZONESIZES AND ASSET BEACON SIGNAL RANGES below.

Dividing a Large Hall into Overlapping Zones

A specific case where using zone center beacons may be advantageous, iswhere zones are selected arbitrarily, and the borders among the zonesare blurred, as will be clarified with reference to the exemplary floorlayout 200E of FIG. 2E.

A large hall 270 is arbitrarily divided into three partly-overlappingzones: West Area 260Z, Central Area 264Z and East Area 268Z. Three zonecenter beacons 260, 264 and 268 are fixed to the ceiling at the centersof the respective zones. A staff member bearing a tag, such as tag 250A,happens to currently visit large hall 270. Upon tag 250A detecting zonecenter beacon 260 (or that the strength of the signal received from zonecenter beacon 260 exceeds a predetermined threshold), tag 250A locatesitself as being currently located within West Area 260Z, and upondetecting asset 230A (actually the beacon of asset 230A) is will authora greeting that locates asset 230A within West Area 260Z. It will benoted that tag 250C will locate itself at both West Area 260Z andCentral Area 264Z, and accordingly may author a greeting locating asset230C at both West Area 260Z and West Area 264Z. It will be also notedthat asset 230C will be located at West Area 260Z by tag 250A. Arecipient of greetings from both tag 250C (locating asset 230C at bothWest Area 260Z and Central Area 264Z) and tag 250A (locating asset 230Cat West Area 260Z only) may apparently locate asset 230C at West Area260Z. Asset 230D will be detected by tag 250D as located at Central Area264Z and asset 230B will be detected by tag 250B as located at East Area268Z. It will be noted that tags 250A-250D may be separate tags borne byseparate staff members, or be a single tag moved within large hall 270by a staff member during routine work, being unaware of the assetlocating activities and corresponding greetings sent by his or her tag.

It will be noted that location ambiguities may be tolerated, or evenremain unnoticed by staff members who are directed to approach a locatedasset. For example, if a staff member is requested to approach asset230C, directing her to either West Area 260Z or Central Area 264Z mayprove very helpful, as long as she does not waste time in looking forthe asset in East Area 268Z. Using homing for finding assets may furtheralleviate location ambiguities, as will be elaborated later below. Theexample of FIG. 2E highlights the fact that zones and borders may partlyoverlap and afford a certain level of ambiguity.

FIG. 2F schematically depicts another exemplary floor layout 200F, thatinclude sixteen room 1N-8N and 1S-8S, a corridor 280, and eight locationbeacons 1-8, that can zone center beacons and/or zone border beacons,fixed to the ceiling and/or walls of corridor 280. Tag 9 identifiesstrong signals received from location beacon 2 and location beacon 3 andaccordingly be located in “zone 2-3”, while tag 10 receiving signalsfrom location beacon 3, location beacon 4 and location beacon 5 may belocated in “zone 3-5”. Assets whose asset beacons are sensed by tag 9 ortag 10 (not shown in FIG. 2F) are reported as located in “zone 2-3” or“zone 3-5”, respectively, which may be very helpful for a staff membersent to approach such assets. Thus, overlapping zones may still be veryuseful in practical applications, and such zones may be defined andnamed in advance, or ad-hoc according to the actual beacons detected bythe tags. It will be noted, however, that signal strength analysis andself-learning may substantially narrow asset locating, for examplelocating tag 10 in “zone 4” instead of “zone 3-5”.

Correlation Between Zone Sizes and Asset Beacon Signal Ranges

Locating an asset by a tag involves two primary stages: (i) identifyingthe tag's current zone, and (ii) detecting the asset via a short-rangesignal received by the tag from the asset's beacon. The conclusion ofthe two stages is that the asset is currently located at the tag'scurrent zone.

Two parameters of interest to the present discussion that affect theeffectiveness and dependability of the above locating process are thesize of zones and the range of the short-range signal received by tagsfrom asset beacons. Within the current section, the two parameters willbe abbreviated “zone size” and “asset signal range”, respectively.

The zone size can be arbitrarily determined by operational and costconsiderations when implementing a system according to the presentdisclosure in a given site. The asset signal range is determined byfactors such as: (i) the signal carrier, such as ultrasound, infrared orlow-power RF; (ii) the strength of the signal transmitted by the beacon;(iii) the sensitivity of the tag's signal receiver; (iv) a thresholdselected for ignoring weak signals received by the tag's signalreceiver; and (v) the permeability of physical partitions that form partof the site, such as walls, to the signal transmitted by the assetbeacon. Generally speaking, factors (i)-(iii) are a matter of design;factor (iv) allows dynamic range adaptation per site or even per zone,as well as calibration according to learning over time; while factor (v)is usually a given design constraint per site, unless extra partitionsare purposely added for separating zones.

The following considerations may affect the design of specificembodiments of the present disclosure, as well as the settings of thesignal threshold (iv) of the previous paragraph:

The asset signal range should be substantially smaller than the zonesize, otherwise identifying the current location of a detected assetwith the current location of the detecting tag may often be erroneous.An exception is when the zones are separated from each other bypartitions (such as walls) that are impermeable to beacon short-rangesignals, which is better achieved with ultrasonic or infrared signals,or by shielding RF-permeable inter-zone partitions if RF signals areused. However, it should be noted that signals that are effectivelyblocked by partitions between zones, may also be blocked by partitionsbetween rooms within a zone, or other random partitions, thereby highlyreducing the number and frequency of useful locating reports, which mayrender the system less effective.

Operationally, larger zones imply reduced specificity when directing astaff member to an asset: “a respiratory machine at the West Zone on the3rd floor” is less specific than “a respiratory machine next to bed C inroom 305”. It is assumed, however, that such reduced specificity isstill good enough for directing staff members toward assets in manysites, which makes larger zones acceptable for such sites.

Smaller asset signal range reduces the number and frequency of usefulgreetings: A greeting is often authored and reported by a randompassing-by tag who happens to detect an asset when moving in itsproximity. A small asset signal range implies that some assets that arecurrently positioned in an area that is seldom visited, may not bedetected by tags that pass-by.

Larger asset signal range introduces locating errors: signalstransmitted by an asset positioned at a certain zone and received andreported by a tag at another zone (such signals will be called herein“leaks”), may introduce errors when directing a staff member to theasset, such as when directing the staff member to the West Zone insteadof the South Zone because of an asset signal that penetrated a wallbetween the zones during the locating phase.

Such error events may be remedies by using homing as part of thedirecting process, which will exploit the very leak that created theerror for correctly directing the staff member toward the asset, ortoward a wall behind which the asset is hiding; also, the staff may getused to a certain low percentage of direction errors and learn toovercome such errors by searching an unfound asset at a neighboringzone.

Resolving conflicting greetings by the recipient: in a busy site, therecipient of the greetings, such as a site database or an assetmanager's portable terminal (see FIG. 4E below) may receive a pluralityof greetings pertaining to the same asset from different tags within ashort period of time. Preferably, the strength of the beacon signalreceived by the tag is included in the greeting (see item (4) in FIG. 4Dbelow), and then greetings associated with stronger signals areconsidered more significant. Also, in case that there is only a singlegreeting and it is associated with a weak signal, the tag zone may bethen presented as approximate location when directing a staff member tothe respective asset.

It will be appreciated that experience and self learning may assist in:(i) fine-tuning the zone allocations (and possibly lead to repositioningsome respective zone border or zone center beacons, if used); (ii)calibrating the relative weights of location signal strengths receivedby the greetings recipient; and (iii) the staff members learning totolerate sporadic direction errors.

Locating People

The system described above uses tags borne by and moving with people tolocate assets via their attached beacons. Tags are typically borne bystaff members, but can be also be borne by residents, customers and/orvisitors.

Locating a person as being in a certain zone via locating his or her tagis often useful by itself. Such tag location is reported by default aspart of a greeting (see FIG. 4D), and can also be reported independentlyof a greeting, for example whenever crossing the border between zones.

Since people may move a lot, real-time reporting is important, whichrequires continuous network communication availability, at least next tothe passages between zones.

Frequency and Validity of Greetings

A greeting is preferably timestamped and authored upon a tag detectingan asset. However, the greeting can be forwarded by the tag only whennetwork communication is available. In addition to availability,communication cost and bandwidth may push toward batching severalgreetings to be sent as a single message.

Assets are usually stationary during service or storage, and therefore agreeting may be considered valid for minutes or even hours from its timestamp. A greeting expiration time may be set according to an asset typeand calibrated by experience; however, in the absence of a freshergreeting, the last greeting received from an asset may be used even pastits expiration time.

A tag that remains in proximity to an asset may detect numerous signalstransmitted by the asset. Following authoring a greeting, subsequentsignals from the same asset may be ignored for a predetermined period oftime, say two minutes, or until a zone change is detected, for examplewhen the asset is moved from one zone to another by the tag bearer.

The more timely a greeting is, the more dependable is the respectiveasset locating data. Accordingly, if available and affordable,continuous network coverage throughout the site is highly preferred.

The Locating Process

FIG. 4A describes an asset locating process by a tag, in a site thatincludes location beacons for locating the tag within a zone (forexample, as described in FIG. 2B, 2D or 2E). In step 401 the tag listensto beacon signals that may arrive from location beacons (zone borderbeacons or zone center beacons) or from asset beacons. If in step 405 abeacon signal is detected, then step 409 checks whether the detectedsignal is from a location beacon or and asset beacon. In case of alocation beacon, the current tag zone as determined from the locationbeacon is recorded in step 413 in the tag's memory, and, if locatingpersons is implemented and communication is available, then in optionalstep 413R the current tag zone is reported to the designated recipient(FIG. 4E).

If step 409 determined that the beacon signal is from an asset beacon,then step 417 checks whether that tag zone is recorded in the tag memoryas a result of a previous loop via step 413, and if so, a greeting isauthored by the tag in step 421, followed by step 425 checking whethercommunication is available. If communication is available, then in step429 the greeting authored in step 421 is sent to the designatedrecipient, possibly along with previous unsent greetings; otherwise thegreeting is batched in step 433, for being sent when communication isavailable.

FIG. 4B describes an asset locating process by a tag using any tag'szone locating method. Thus, in step 401B the tag's current zone islocated using any tag locating method, such as the beacons in FIG. 2B,2D or 2E; or the turn analysis and/or visual features of FIG. 2C; or bydetection and analysis of irregularities in the earth's magnetic fieldof U.S. Pat. No. 8,798,924 depicted above; or any other applicableindoor positioning method. In optional step 413B, the tag's current zoneis reported if locating persons is implemented and communication isavailable. In step 401B the tag listens to asset beacon signals. If instep 405B an asset beacon signal is detected, then a greeting isauthored in step 421. If step 425 finds out that communication isavailable, then in step 429 the greeting authored in step 421 is sent tothe designated recipient, possibly along with previous unsent greetings;otherwise the greeting is batched in step 433, for being sent whencommunication is available.

FIG. 4C describes an asset locating process similar to the process ofFIG. 4B, while also checking and reporting escorting events. Thus, instep 401B the tag's current zone is located using any tag locatingmethod. In optional step 413B, the tag's current zone is reported iflocating persons is implemented and communication is available. In step401B the tag listens to asset beacon signals. If in step 405B an assetbeacon signal is detected, then in step 419 the tag checks whether thetag and the detected asset are in escorting mode, which is when the tagand the asset maintain a closed proximity for a duration of at least apredetermined period of time, such as thirty seconds, and the tagdetects that it has moved during that period, such by detecting changeof zone or according to motion detection by an accelerometer included inthe tag's sensors 138 (FIG. 1). If escorting is not detected, then agreeting is authored in step 421; otherwise is step 421E, a greetingmessage that include escorting information (FIG. 4D) is authored. Ifstep 425 finds that communication is available, then in step 429 thegreeting authored in step 421/421E is sent to the designated recipient,possibly along with previous unsent greetings; otherwise the greeting isbatched in step 433, for being sent when communication is available.

Greeting Contents

FIG. 4D schematically describes the contents of a greeting 440 sent by atag to a recipient, to report that the tag has detected asset X in zoneY. Out of fields (1)-(8) of the greeting, only field (6)—the identity ofthe detected asset—is mandatory, while the other seven fields may beoptional, implicit, or otherwise available to the recipient.

Field (1) identifies the greeting recipient or recipients (see FIG. 4E)which may be the same for all greetings in the site (e.g. a site server)hence redundant. Field (2) identifies the sending tag, which may be alsoderived from the network communication protocol hence redundant. Field(3) indicates the time when the tag detected the presence of the asset,which may be essentially identical to the time of receiving the messageby the recipient, if real-time communication is implemented. Field (4)reports the strength of the beacon's signal detected and measured by thetag, if this feature is implemented; weaker signals may indicate largerdistance and/or obstructions between the tag and the beacon, which mayassist the recipient in deciding between conflicting greetings receivedat a similar time from different tags and locating the same asset atdifferent zones.

Field (5) reports the zone where the asset is located, which is the zonewhere the tag is or has been located at the moment of detecting thetag's location. In implementations of the present disclosure wherepersons are continually located by their tags and where greetings aresent in real-time, the current zone of the tag may already be known tothe greeting recipient, which may make field (5) redundant.

Mandatory field (6) identifies the detected asset, directly or viaidentifying the respective beacon attached to the asset, such as byinventory number an/or detailed description.

Field (7) indicates whether the greeting is produced in connection withan escorting event (FIG. 4C) which usually suggests that the detectedasset has been moved by the tag bearer. Such information can be usefulin various ways: (a) identifying unauthorized moving of assets; (b)referring questions regarding the current location of the asset to therespective tag bearer; (c) identifying the current mover as thepreferred mover for the next moving of the same asset, since the currentmover is already familiar with the current location of the asset withinthe zone; or (d) if the reporting tag is borne by a designated mover ofthe asset, the asset may be presumed to have been relocated to thedesignated moving target location, such as “next to bed C in room 305”.

Field (8) is for implementations where the asset beacon 150 includes andemploys an asset interface 158 for receiving status messages from theasset, such as usage, material inventory or need for maintenance. Suchmessages are included in field (8) to be handled by the messagerecipient.

Recipients of Greetings

A greeting is intended to update a location data store 170 of arecipient, as to where the respective asset is located. FIG. 4Eschematically introduces three typical recipients that may benefit fromreceiving greetings.

In a common scenario, greeting-sending tag 450 addresses its greetingsto site server 458 such as a central hub of administrative informationin the site. Any would-be user of asset location information may thenconnect with site server 458 for retrieving the requested information.

Alternatively or additionally, in sites that employ an asset manager whois in charge of assets, greetings may be sent to asset manager'sportable terminal 454, such as a tablet, mobile phone, or an enhancedstaff tag, to allow the asset manager to conveniently and continuouslymonitor all assets.

Alternatively or additionally, in sites that employ staff members whoare often assigned moving tasks, an extended asset mover's tag 462 mayreceive greetings from greeting-sending tags 450, so that when the moveris sent to urgently fetch “the yellow respiratory machine” he'll havethe respective location information readily-available at hand in hos ownstaff tag. Optionally, such location data may be retrieved on-demand, byasset mover's tag 462 sending a query to all tags, which can beinformally described as asking all tags “who has seen the yellowrespiratory machine during the last hour?”, which is then responded bygreetings sent from only the tags which have recently detected thesought asset.

Escorting

FIG. 5 further elaborates on escorting events depicted above withreference to steps 419 and 421E of FIG. 4C.

Detection of escorting events comes to identify that an asset is movedby a tag bearer, usually a staff member. A first condition for escortingis learning, from the asset beacon signal received by the tag, that theasset and the tag are in close proximity. To avoid false detection of anescorting event when the tag just passes by the asset, a secondcondition for escorting is ensuring that the close proximity ismaintained for a prolonged duration, such as 30 seconds or more. Tofurther avoid false detection in case that a staff member happens tostand in close proximity to an asset for a prolonged time, such as anurse standing next to an asset while taking care of a resident, a thirdcondition is detecting that the tag, apparently together with the asset,have moved while maintaining the close proximity.

In step 501 a tag seeks signals from asset beacons and in step 505 anasset beacon is detected. Step 509 learns from the strength of thesignal received from the asset beacon whether the asset and the tag arein close proximity, such as a meter or less. If yes, then step 513checks whether the close proximity is maintained for a prolongedduration, such as thirty seconds or more. If so, then step 515 checkswhether the tag has moved while the closed proximity has beenmaintained, for example by detecting that the tag has crossed a borderbetween zones and/or by consulting an accelerometer or camera includedin sensors 138 of the tag. A positive outcomes in all three steps509-515 identifies an escorting event, which implies that the asset hasbeen moved by the tag bearer, which conclusion is identified and/orreported in step 519. Step 525 checks whether the staff member bearingthe tag had a moving assignment for the detected asset, and if yes, thenstep 529 sets the current location of the asset according to the targetof the moving assignment, such as next to bed C in room 305, which ismore specific than locating the same asset at the West Zone as in thegeneral locating case.

It will be appreciated that while steps 501-515 are performed by thetag, steps 519-529 may be performed by the tag, or, additionally oralternatively, by recipients to which the tag reports, such as siteserver 458, asset manager's portable terminal 454, or asset mover's tag462 of other movers (see FIG. 4E). In any case, the end result of theprocess is that the current location of the moved asset is updated to bethe target location specified in the moving assignment.

Directing a Staff Member Toward a Tag

FIG. 6 describes a process of directing a staff member toward an assetfor performing an asset-related task, such as repairing, replenishingsupplies, moving the asset to a new location, or just visiting the assetby a security attendant. The steps on the left hand side of the chartare performed by a control computing device (see control 174 in FIG.1A), while the steps on the right hand side are performed by the tag ofa staff member designated to approach the asset.

In step 601 control generates or receives a task that requires visitinga specific asset, herein called asset X. Generation of a task by controlcan be made automatically for repair, replenishment or security tasks,or entered manually into the control by a supervisor, for example whenthe asset is needed in a certain place, in which case the task is anasset relocation task. In step 605 control retrieves the identifier ofthe beacon attached to asset X, for example from location data store 170of FIG. 1A, and in step 609 control retrieves, also from location datastore 170, the current zone of asset X most recently reported by alocating process, such as the processes of FIG. 4A-4C or 5 above. Instep 613, a staff member is selected for performing the task, which canbe made automatically, for example where there is just a single staffmember on duty that is suited for the task, or via a manual inputreceived by control from a supervisor. In step 617, the description ofasset X, the current zone of asset X, the respective beacon identifierand the task description are provided by control to the staff tag of theselected staff member.

In step 621 the staff tag of the selected staff member receives the dataprovided by control in step 617. In step 625 the tag presents the zoneto and is moved to the zone by the staff member who bears the tag. Step629 initiates a homing process, in which the tag seeks signals thatcarry the beacon identifier, and when such signals are detected, the tagguides the staff member toward the asset by providing homing indiciatoward the beacon (FIGS. 7A-7C below). In step 631 the tag reaches assetX, which enables the staff member to perform the task.

Steps 633-641 pertain to the case where the assigned task is moving theasset to a new target location. In this case, in step 633 the tagdetects an escorting event, which implies that the asset is moved by thestaff member who bears the tag. In step 637 the tag detects, from theweakening or disappearance of the beacon signal, the departure of thestaff member from the asset hence the purported completion of the movingtask, which lets control, in step 641, to record the new location ofasset as the target of the moving task.

Homing

FIGS. 7A-7C summarize and highlight some aspects relating to homing, inaddition to aspects pertaining to homing presented in pervious sections.FIG. 7A presents an asset 700 to which an asset beacon 700B is attached.Asset beacon 700B recurrently transmits short-range signal 704, such asan infrared, ultrasonic or a low-power RF signal, which is received byshort-range signal receiver 114 of tag 110. Tag 110 interpretsshort-range signal 704 for both identifying asset beacon 700B andmeasuring the strength of the received signal, which is generallyproportionate to the distance between the tag and the asset. Display122D and/or speaker/earphone 122A serve to provide visual and/or audioindicia of the current measured signal strength, which serve to guidethe staff member who carries the tag toward the beacon, hence toward theasset. FIG. 7B schematically describes indicia displayed on display 122Dof tag 110. Thus, text 720 displays the signal strength in numericterms, preferably using distance units for presenting the estimateddistance between the tag and the asset derived from the signal strength;signal level bar 710 shows graphically current signal level 710L; whilebeacon pointer 714 show the estimated beacon direction, derived from aseries of signal strength readings during the motion of the tag incombination with readings from a compass and/or accelerometer includedin sensors 138 (FIG. 1A).

FIG. 7C schematically demonstrates how homing may remedy locatingerrors, using a scenario based on the southwest corner of the floorlayout of FIGS. 1A-1B. An asset 230 is located in a corridor 212 that isvery rarely visited by tag-bearing persons. The corridor 212 has beenassigned to the South Zone, while a frequently-visited neighboring room210 has been assigned to the West Zone. The wall between room 210 andcorridor 212 is sufficiently permeable to RF asset beacon signal 230S toallow a tag 250 visiting room 210 to detect asset 230. During thelocating phase, several tags visiting room 210 mistakenly report thatasset 230A is located at the West Zone, and its correct location in theSouth Zone is not reported simply because no tag happens to visit thedeserted corridor 212. However, when a staff member is directed to visitasset 230 in the West Zone, he uses his tag 250 to quickly screen allthe rooms of the West Zone, including room 210. When in room 210, tag250 detects asset 230 via RF asset beacon signal 230S, and the homingprocess directs the tag bearer toward the wall, which will lead mostreasonable staff members to search and find asset 230 behind the wall,in corridor 212 that belongs to the South Zone. Thus, the very leak thatcauses the locating error during the locating phase, helps to recoverfrom this error during the directing phase.

Blind Areas

A “blind area” is an area that may host assets but is seldom or neveraccidently visited by passing-by tags. FIG. 8A schematically describesfloor layout 800A that includes blind area 802A and blind area 802B thatare positioned at dead ends of a corridor and are visited just once aday by the cleaner, while blind area 802C is a closet or a storage roomthat may store assets.

Blind areas may collectively form a “blind zone” that is systematicallyscreened by staff members when an asset is not found in its lastreported location, or security personnel or other staff members may bedirected to periodically, say once per hour, pass through all blindareas. Such a security screening may also be initiated when a certainasset is not reported by any greeting during an extended period of time,say three hours. Alternatively, an asset beacon detector 820 may be usedto cover a blind area, as described below with reference to FIG. 8B.

Security and Beacon Detectors

It is a clear interest of a site to prevent assets from being stolen ormisplaced to another floor or section.

Beacons should preferably include tamper-detection sensors, that turn onan audible alarm and/or turn the beacon's short-range signal into analarm signal. Accordingly, routinely locating an asset within itsdesignated area verifies that the asset has not been misplaced orstolen.

On the other hand, failure to locate an asset for extended time mayimply either that the asset has been misplace or stolen, or that theasset is currently located in a blind area. Both situations can bepreempted by deploying beacon detectors in selected areas.

A “beacon detector” is essentially a tag that is fixed at a selectedlocation, such as a ceiling or a wall, for detecting assets in itsproximity. Its design is similar to tag 110 of FIG. 1A, modified forcontinuous operation in a fixed location, which implies continuousnetwork connection and preferably drawing energy from the site'selectrical network.

FIG. 8B describes a floor layout 800B that employs beacon detectors fortimely locating and detecting assets. Floor layout 800B has two exits:elevator 204 and staircase 806. Security beacon detectors 820A-820B arepreferably fixed next to the exits, and upon detecting an approachingasset and checking that moving the asset has not been authorized, theevent is reported, an alarm may be triggered and/or the respective exitmay be locked. Beacon detectors 810A-810C are fixed in the blind areas802A-802C of FIG. 8A, and periodically report the location of assetsthat are contained within the blind areas.

Multi-Function Smart Devices

The active devices discussed so far can be divided into:

(a) tags borne by persons for detecting beacons,

(b) location beacons for assisting tags in locating themselves withinzones,

(c) asset beacons for being detected by tags, and

(d) fixed beacon detectors that are tag-like devices fixed within blindareas or at exits.

In some embodiments it may be advantageous to combine several tag/beaconfunctions into a single enhanced smart device as described below.

Referring to FIG. 9A, smart device 900 is devised to serve as anenhanced tag or enhanced fixed beacon detector. Short-range signaltransceiver 904 may act, in addition to receiving short-range signals asin the case of short-range signal receiver 114 of tag 110 in FIG. 1A,also as a short-range signal transmitter, allowing smart device 900 toact also as a beacon. Network communication device(s) 908 may beenhanced to not only act as a network connection means that serves tag110, but also as an access point that serves other smart devices thatlack a continuous network connection of their own and pass by smartdevice 900; for example, network communication device(s) 908 may useboth a cellular network connection and a local Wi-Fi or Bluetooth linkto offer a cellular hotspot to passing-by smart devices. User interface912 may be reduced or eliminated in comparison to user interface 122 incase that smart device 900 is fixed to a location. Processor 130 isenhanced, compared to processor 130 of tag 110, to accommodate the addedfunctionalities described herein. In case of a fixed installation, powersupply 924 may draw power from the site's electrical network, andsensors 928 may be eliminated or reduced to camera-only, for example.Attachment 932 may be suited for fixed installation, while otherfunctions 936 may be nullified in case that smart device 900 isdedicated solely to location-related functions.

FIG. 9B uses a floor layout 940 for demonstrating several exemplarysmart device implementations. Smart devices 948 are positioned in blindareas 944 for detecting assets and reporting their location. A smartdevice 948 is preferably fixed to the wall or ceiling within or next tothe respective blind area, and is preferably equipped with continuousnetwork connection and draws power from the site's electrical network.Smart device 954 is positioned next to the elevator door and may serveseveral functions: (i) a zone border beacon for allowing tags locatetheir entry into or exit from the Elevator Zone; (ii) a security objectdetector for detecting objects that are not permitted to leave the zonewithout suitable escorting; (iii) a network communication access pointallowing passing-by tags establish network connection. Smart device 952may be similar to smart device 954, preferably except the beaconfunctionality. Smart devices 950 in a minimal configuration may operateas both zone border beacons (see 220A-220D of FIG. 2B) and access pointsthat provide network communication to tags upon crossing borders betweenzones, which implies continuous zone-level locating of all tag-bearingpersons crossing the respective borders. Smart devices 950 may befurther enhanced, to act also as beacon detectors, in which casezone-level locating of all assets can depend on smart devices 950+954alone, thereby obviating that need for locating and greeting activitiesby moving tags 250. It will be appreciated, however, that in order todepend solely on smart devices 950 for asset location, continuouselectricity and communication supply to smart devices 950 becomemandatory, which requires substantially more investment ininfrastructure modifications, compared to when using zone border beaconsas in floor layout 200B of FIG. 2B, since beacons can operate for monthsand years on battery power and the configuration of FIG. 2B does notmandate continuous communication at each location beacon. Accordingly,in some cases an installation of a locating system according to thepresent disclosure can start with zone border beacons 220A-220D of FIG.2B, and be later upgraded by supplementing or replacing zone borderbeacons with smart devices 950 of FIG. 9B, which may be made graduallyor at once. Smart device 958 is essentially identical to tags 250, withthe addition of a mobile access point, such as a mobile Wi-Fi hotspotthat connects to the network via cellular communication, for servingsimpler passing-by tags that have no cellular communication of theirown.

Multi-Level Border Control

Asset security has been discussed above with reference to FIG. 8B, wheresecurity beacon detectors 820A+820B positioned next to the exits fromthe floor area detect approaching assets and trigger an audible alarmand/or lock the respective exit upon finding out that moving the assetout of the floor area has not been authorized. It will be appreciatedthat such alarm or exit lock events may be annoying to uninvolvedpersons in the area, and the following arrangement comes to reduce thefrequency of such annoyance by earlier detection and preemption of suchevents.

The forthcoming discussion covers locating and securing both assets andpersons, and will therefore relate to locating and securing “restrictedobjects” that require authorization in order to move or be moved out ofa predefined area, called herein a “confined area”. Restricted objectscan be “restricted assets” that are supposed to stay at a predefinedconfined area, or persons, such as certain residents (“restrictedresidents”) in a healthcare facility, that require special attention andsupervision.

FIG. 10A depicts a of a confined area 960 that accommodates restrictedobject 964A and restricted object 964B, each can be an asset or a personthat is designated to normally stay only within the safe area. The term“area” is used herein to avoid confusion with the term “zone” usedabove, and it will be appreciated that both zones and areas may be usedconcurrently in sites that implement both general locating as depictedabove, and the security feature discussed hereinbelow. A “buffer area”is an area where a restricted object is not supposed to stay withoutauthorization, but is otherwise harmless. Authorization may be in theform of a temporary permit received from a senior staff member, or byrecognizing that the object is accompanied by an authorized person, suchas a designated staff member or a trusted family member identified byhis or her tag or beacon. Such escorting may be recognized by a tag of aauthorized person or of a restricted object that detects that closeproximity is maintained between the authorized person and the restrictedobject for an extended period of time, similarly to detecting escortingevents according to FIG. 5, or by detecting simultaneous proximity ofboth a restricted object and an authorized person to a fixed tag orbeacon. The buffer area is preferably used to provide an early warningand early intervention opportunity for staff intervention, in case thata restricted object is detected entering or within the buffer areawithout authorization. If a restricted object further moves or is movedthrough the buffer area and is detected to appear without authorizationat the “lock area”, some or all exits from the lock area, such aselevator 204 and/or the door of staircase 906, automatically lock,possibly selectively according to that detected location of therestricted object, to minimize annoyance to uninvolved persons. If, forone reason or another an exit fails to lock, as may occur in the case of“tailgating”, i.e. a restricted person following an unrestricted personwhile keeping the exit open, the restricted object enters withoutappropriate escorting the “alarm area”, which is not explicitly markedin FIG. 10A, and consists of the elevator 204 and the staircase 906,which triggers an alarm. It will be appreciated that a generous bufferarea will effectively eliminate the great majority of exit lockingevents, while a sufficient lock area may turn alarms into extremely rareoccasions. It will be noted that in a certain embodiments, differentrestricted objects or groups of restricted objects within the same floormay be allocated separate safe areas, in which case safe areas andbuffer areas may be individually allocated for such objects or groups ofobjects.

It will be appreciated that the terms safe area, buffer area, lock areaand alarm area defined above are used for brevity and clarity, andrepresent concepts that may be described and elaborated usingalternative terms without deviating from the underlying structural,logical and operational concepts.

In the embodiment of FIG. 10A, object beacon 966A is attached torestricted object 964A while object beacon 966B is attached torestricted object 964B, where the term attached preferably meansphysical attachment in case of an asset, or a convenient wearing orcarrying arrangement in case of a person, with tamper-detection meanspossibly implemented in both cases. Fixed tag 968B and fixed tag 968Care positioned at the passages between the safe area and the buffer areafor detecting entry of a restricted object into the buffer area.Optionally, additional fixed tags 962B may be scattered within thebuffer area to detected restricted objects with the buffer area.Possibly, in some implementations, fixed tag 968B and fixed tag 968C, aswell as fixed tags 962B, may also be configured to autonomously detectand select nearby staff members and alert them, via their tags, tohandle the event and move or accompany the respective restricted objectback to the safe area. Fixed tag 968D and fixed tag 968E are positionedat the passages between the buffer area and the lock area for detectingentry of a restricted object into the lock area. Optionally, additionalfixed tags 962L may be scattered within the lock area to detectedrestricted objects with the lock area. Possibly, in some embodiments,fixed tag 968D and fixed tag 968E, as well as fixed tags 962L, arepreferably also configured to autonomously send a locking signal to theelevator 204 and door of staircase 906. It will be appreciated that theconcept of locking an elevator may be actually implemented by preventingthe elevator door from closing, or by disabling the elevator altogethertrough the elevator's controller (not shown). Fixed tag 968F and fixedtag 968G are positioned at the exits, i.e. the passages between the lockarea and the alarm area, for detecting entry of a restricted object intothe alarm area, i.e. within the elevator or staircase. Possibly, in someimplementations, fixed tag 968F and fixed tag 968G are also configuredto autonomously trigger an audible alarm and initiate an alarm eventprocedure such as calling for intervention by security personnel. Itwill be appreciated that fixed tags 968B-968G, 962B and 962L in theexemplary embodiment of FIG. 10A, are beacon detectors fixed at aselected points, such as on a ceiling or a wall, for detecting objectbeacons in their proximity. Their design is similar to tag 110 of FIG.1A, modified for continuous operation in a fixed location, whichpreferably implies continuous network connection and drawing energy fromthe site's electrical network.

FIG. 10B depicts an embodiment of a confined area 970 that is similar tothe embodiment of FIG. 10A, except for swapping the roles of tags andbeacons. Thus, in confined area 970, restricted object 974A andrestricted object 974B bear smart object tag 976A and smart object tag976B, respectively. Border beacon 978B and border beacon 978C cooperatewith the smart object tags to detect, by the tags, crossing the borderbetween the safe area and the buffer area; border beacon 978D and borderbeacon 978E cooperate with the smart object tags to detect, by the tags,their crossing the border between the buffer area and the lock area; andborder beacon 978F and border beacon 978G cooperate with the smartobject tags to detect, by the tags, their crossing the border betweenthe lock area and the alarm area. Location beacons 972B and 972L areoptionally added for the detection of restricted objects, by their tags,within the buffer area and lock area, respectively. It is the smartobject tags that either report border crossings or unauthorized locationto a control, or are configured to autonomously trigger a staff, lock oralarm action respective to the detected border crossing, as depictedwith reference to FIG. 10A above.

FIG. 10C describes a scenario of a confined area 980 that is similar tothe scenario of FIG. 10A, except that fixed tags 968B-968G are replacedby cameras 988B-988G, respectively; while object beacons 966A-966B arereplaced by visual features 986A-986B, respectively. Visual features986A-986B may identify restricted objects either individually, forexample by including a machine-readable identifier, such as amachine-recognizable text, QR code or bar code, or identify group ofrestricted objects, such as restricted residents or restricted assets,for example by a distinctive color of a label or a dress. When any ofcameras 988B-988G detects any of visual features 986A-986B crossing aborder between zones, a respective processor, such as the processor of afixed tag that includes the camera or of a control reported by thecamera, may actuate an action such as calling for staff intervention,locking exits or triggering an alarm, as depicted above with referenceto FIG. 10A. In some embodiments, for security and/or restrictedresident dignity, visual features my be marked in the invisiblespectrum, for example in the infrared spectrum, with the cameras usingappropriate filters to recognize such visual features. It will beappreciated that additional cameras may be fixed and operate within thebuffer area and the lock area similarly to tags 962B and tags 962L ofFIG. 10A.

It will be noted that by using fixed tags that include cameras, thescenarios of confined area 960 and confined area 980 may be combined, sothat some restricted objects my be detected and identified by theirobject beacons, while other restricted objects my be detected andidentified by their visual features. It will be also noted that thatarchitectures of FIGS. 10A-10C may be combined and mixed, for example byrestricted residents bearing tags while restricted assets having beaconsattached to them.

It will also be noted that in the embodiments of FIGS. 10A-10C, a tag ora camera cooperates with a beacon or a visual feature to recognize thatan asset is moving from one area to another or is already in the bufferor lock area. There are two further steps that may be performed,according to the system architecture, by either the tag or by a control(such as control 174 of FIGS. 1A-1B) to which the tag or camera isreporting: (a) deciding whether the detected moving of the respectiverestricted object is authorized or not; and (b) triggering an action,such as: selecting and calling staff members to intervene; lockingexists; or actuating an alarm.

FIG. 11A depicts the operation of the multi-level border securityarrangement described with reference to FIGS. 10A-10C above. In step1001, a restricted object, such as a person or an asset, is detectedcrossing a border between areas. Such detection is made via a tagdetecting a beacon under the arrangement of either FIG. 10A or thearrangement of FIG. 10B, or by a camera detecting a visual feature underthe arrangement of FIG. 10C. Step 1005 decides whether the bordercrossing is authorized or not. If the border crossing is authorized, byeither a permit received via communication from a supervisor, or byverifying, via a personal tag or beacon of a person that maintains closeproximity to the restricted object, that the restricted object isaccompanies by a person authorized to move the restricted object, thenstep 1005 loops back to wait for another border crossing detection. Ifstep 1005 concludes that the border crossing is not authorized, thenstep 1009 decides, according to the type of border crossed, what actionto take. If the detected crossing is from the safe to the buffer area,then step 1013A triggers a notification to the tag or tags of one ormore selected staff members in the vicinity of the crossing point, torush and accompany the crossing restricted object back to the safe area.In the action is picked and acknowledged in steps 1013B by one of thenotified staff members, then in step 1013C the incident is reported; ifstep 1013B does not receive acknowledgement within a short period, thenthe process loops back to step 1013A to call for action of additionalstaff members. If the crossing is found by step 1009 to be from thebuffer to the lock area, then step 1017 triggers locking or disablingthe respective exist(s), such as the elevator and the staircase door. Ifthe crossing is found by step 1009 to be from the lock area to the alarmarea, then step 1021 triggers an alarm. If the crossing is found by step1009 to be downstream, i.e. from the alarm to the lock area, from thelock area to the buffer area, or from the buffer area to the safe area,then step 1025 triggers a step-back procedure, such as turning an alarmoff or unlocking exits, and an update describing the crossing event issent to the involved staff members.

FIG. 11B is similar to FIG. 11A, except that a restricted object isfirst detected in step 1001A within the buffer area, lock area or alarmarea, instead of at the respective border; for example, when thedetection is made by fixed tags 962B or fixed tags 962L within therespective area (FIG. 10A), rather than at the respective borders byfixed tags 968B-968E. Step 1005A compares the current location to thelast known location to interpret that current location as a bordercrossing event, and checks whether the crossing was authorized. Ifcrossing is found not authorized, then step 1009A diverts to actionsaccording to the nature of the crossed border, as depicted in FIG. 11Aabove.

FIG. 12 is a flowchart that describes an authorized relocation processof a restricted object. In step 1201 a restricted object is moved to anew location according to the process of FIG. 11 or FIG. 11A. Since allborder crossings are authorized, all border crossings are performedwithout step 1005/1005A triggering any of the actions that follow step1009/1009A. When reaching the intended location, then step 1205 resetsthe definitions of the safe area and buffer area of the moved objectaccording to the new current location. For example, in a healthcarefacility, a restricted resident is escorted by a staff member to a largedining room for lunch and is left by himself at the dining room, thatresident's safe area may be redefined to encompass the dining room, andleaving the dining room without escorting by an authorized person willthen trigger step 1013A of FIGS. 11/11A. Such relocation andredefinition of the safe and buffer areas may be recorded centrally, ina system that tracks objects and/or personalizes safe areas perrestricted object, or just be established de-facto, by the very presenceof a restricted object in a new area that is generally defined as a safearea.

It will be reemphasized that the steps of FIGS. 11A, 11B and 12 may beperformed, according to selected system architectures, individually orcooperatively, by processors of a staff tag, a resident tag, an assettag, a fixed tag or a control. Accordingly, the expression “at least oneprocessor” that perform part or all of the steps of the process of FIG.11/11A may relate to performing steps by any one or combination ofprocessors included in participating tags, controls and/or servers.

Non-Healthcare Applications

For clarity and consistency, the exemplary embodiments depicted aboverelated primarily to healthcare facilities. It will be appreciated,however, that the teachings of the present disclosure may selectivelypertain a to variety of institutional sites, such as manufacturingplants, educational institutions, government buildings, office building,ships, etc., that can benefit from zone-level locating of objects ormulti-level border control.

Self Learning, Calibration and Improvement

The systems and methods depicted above are expected to produce tangibleand measurable results in locating and securing assets, in effectivelydirecting staff members toward selected assets, and in border controlwithin sites. Exceptions are easily noticed: an asset whose locationremains unknown for a prolonged duration; misdirecting a staff membertoward an asset; or a staff member spending excessive time in screeninga zone for finding an asset.

Exceptions may be automatically detected at location data stores andcontrols (FIG. 1B), and/or manually reported by staff members. Suchexceptions may motivate and guide redefining zones, better placinglocation beacons, adding beacon detectors, changing the sensitivitythreshold of tag receivers, upgrading the network communication, orrevising the criteria for deciding between conflicting locating reports.

Improvement can be also made by educating and training staff memberswith regard to where to move assets that completed a task, for exampleinto preassigned asset parking areas; how to report the location of anunused asset; or who is authorized to move a certain asset. Visitors mayalso be educated, via signs and brochures, to request staff assistancefor moving an unused asset and never move an asset by themselves.

The above measures may substantially improve the performance of locatingand securing assets with minimal additional investment in hardware andinstallation.

CONCLUSION

The systems and methods taught by the present disclosure provide acompact locating and directing system for assets and people, that can beafforded by and adequately serve many sites that cannot or will notafford conventional RTLS, access control or security systems.

While the invention has been described with respect to a limited numberof embodiments, it will be appreciated by persons skilled in the artthat the present invention is not limited by what has been particularlyshown and described herein. Rather the scope of the present inventionincludes both combinations and sub-combinations of the various featuresdescribed herein, as well as variations and modifications which wouldoccur to persons skilled in the art upon reading the specification andwhich are not in the prior art.

What is claimed is:
 1. A method of operation of a tag for locatingassets, the tag is borne by and occasionally moving with a user within asite that is divided into a plurality of zones, the method comprising:receiving a first short-range signal from a location beacon associatedwith a current zone of the plurality of zones; receiving a secondshort-range signal from an asset beacon attached to an asset; retrievingfrom the second short-range signal an identification of at least one ofthe asset beacon or the asset; wirelessly reporting the current zone toa recipient; and wirelessly reporting the identification to therecipient.
 2. The method of claim 1, further comprising: checkingavailability of a network connection; and wherein at least one of thereporting the current zone or the reporting the identification ispostponed until the checking is positive.
 3. The method of claim 1,wherein the reporting the current zone and the reporting theidentification are included within a single locating message.
 4. Themethod of claim 1 wherein the reporting the current zone isautomatically made following the receiving a first short-range signalfrom a location beacon, and the reporting the identification isautomatically made following the receiving a second short-range signalfrom an asset beacon.
 5. The method of claim 1, wherein the user is astaff member and the tag is a staff tag that is further operative fordirecting the staff member toward target assets, the method furthercomprising: receiving a target asset identifier and a target zoneassociated with a target asset; presenting to the staff member adescription of the target asset; and presenting to the staff memberdirections for reaching the target zone.
 6. The method of claim 5,wherein the staff member is designated to relocate the target asset, themethod further comprising: receiving a relocation assignment identifyinga target location for the target asset; detecting short-range beaconsignals transmitted by a beacon of the target asset; learning from thebeacon signals that the staff tag and the beacon are in close proximity;measuring the duration of the close proximity; checking whether thestaff tag has moved while the close proximity is maintained; and basedon the results of the measuring and the checking: locating the targetasset at the target location.
 7. The method of claim 5, furthercomprising: seeking beacon signals that match a beacon identifier of abeacon attached to the target asset; and upon detecting a beacon signalthat matches the beacon identifier: producing a series ofhuman-comprehensible homing directions for approaching the target asset.8. The method of claim 7, wherein: the directions for reaching thetarget zone including at least one of: a name of the target zone, orinstructions for reaching the target zone; the step of presentingdirections including at least one of: displaying text instructions,displaying graphical guidance, or playing audio instructions; and thestep of producing a series of homing directions including at least oneof: displaying a textual representation of a current strength of thedetected beacon signal, displaying a textual guidance regarding thedirection of the beacon, displaying a graphical representation of acurrent strength of the detected beacon signal, displaying a graphicalguidance regarding the direction of the beacon, playing an audio signalthat is indicative of the current strength of the detected beaconsignal, or playing an audio guidance regarding the direction of thebeacon.
 9. A tag for locating assets, the tag is for being borne by andoccasionally moving with a user within a site that is divided into aplurality of zones, the tag comprising: a short-range signal receiver; anetwork communication device; and a processor controlling theshort-range signal receiver and the network communication device, theprocessor is programmed to: receive a first short-range signal from alocation beacon associated with a current zone of the plurality ofzones, receive a second short-range signal from an asset beacon attachedto an asset, retrieve from the second short-range signal anidentification of at least one of the asset beacon or the asset,wirelessly report the current zone to a recipient, and wirelessly reportthe identification to the recipient.
 10. The tag of claim 9, wherein theprocessor is further programmed to check availability of a networkconnection, and wherein at least one of the report the current zone orthe report the identification is postponed until the check is positive.11. The tag of claim 9, wherein the report the current zone and thereport the identification are included by the processor within a singlelocating message.
 12. The tag of claim 9, wherein the report the currentzone is automatically made following the receive a first short-rangesignal from a location beacon, and the report the identification isautomatically made following the receive a second short-range signalfrom an asset beacon.
 13. The tag of claim 9, wherein the user is astaff member and: the tag is a staff tag that further comprises a userinterface for directing the staff member toward target assets; and theprocessor is further programmed to: receive a target asset identifierand a target zone associated with a target asset, present to the staffmember a description of the target asset, and present to the staffmember directions for reaching the target zone.
 14. The tag of claim 13,wherein the staff member is designated to relocate the target asset, theprocessor is further programmed to cooperate with the short-range signalreceiver and the network communication device to: receive a relocationassignment identifying a target location for the target asset; detectshort-range beacon signals transmitted by a beacon of the target asset;learn from the beacon signals that the staff tag and the beacon havereached close proximity; measure the duration of the close proximity;check whether the staff tag has moved while the close proximity has beenmaintained; and based on the results of the measure and the check:locate the target asset at the target location.
 15. The tag of claim 13,wherein the processor is further programmed to cooperate with theshort-range signal receiver to: seek beacon signals that match a beaconidentifier of a beacon attached to the target asset; and upon detectinga beacon signal that matches the beacon identifier: produce a series ofhuman-comprehensible homing directions for approaching the target asset.16. The tag of claim 15, wherein: the directions for reaching the targetzone include at least one of: a name of the target zone, or instructionsfor reaching the target zone; the step of present directions includes atleast one of: display text instructions, display graphical guidance, orplay audio instructions; and the step of produce a series of homingdirections includes at least one of: display a textual representation ofa current strength of the detected beacon signal, display a textualguidance regarding the direction of the beacon, display a graphicalrepresentation of a current strength of the detected beacon signal,display a graphical guidance regarding the direction of the beacon, playan audio signal that is indicative of the current strength of thedetected beacon signal, or play an audio guidance regarding thedirection of the beacon.